Nitrogen, heat, and water usually makes sweet. Sometimes young trees need a few years to produce the best fruit.

My satsumas were extremely late because of the late spring and a very cloudy fall. They did not get sweet until January. I have Kimbrough and Brown Select. We had a forecast of 40 deg for the morning of May 10. Satsumas are good temperate climate citrus because they resist blooming until the spring has actually sprung. I never had May blossoms
before.

John says heat but I think he actually means sunlight, which I regard as much more important than nitrogen. Plants need water, CO2 and photons to make sugar. We do not fertilize after May or June and lack of nitrogen has never been a factor making our fruit sweet. On a wet, cloudy fall/winter there is usually a problem with sweetness coming late.

my trees are about 4 years old and they produced a very good crop of sweet oranges last year. this year the crop was good but the oranges never passed to the sweet stage, they went from getting sweet to sour. most of the people with satsumas around had large crops of sweet oranges, even after these freezes. I have a watering system for them so they don't lack water or sun.
thanks,
papapar

I have a few questions about my young owari satsuma...I live in Central FL and since I do not get a lot of very cold nights below 37 degrees (maybe 2-3 weeks at the most) for the whole winter will this make my Satsuma not ripen properly? I thought I read they needed a lot more cold weather to ripen and sweeten compared to other Citrus Our oranges and Tangerines don't normally ripen till Jan or Feb. depending on the variety... Also I thought I read that in my area Satsumas ripen around Oct/Nov...is this true? Due to lack of chill hours in late fall/early winter, and does that mean my satsuma won't turn orange due to lack of cold weather. We're almost always in the 80's till the end of Nov and sometimes till early to mid Dec...

Its a young tree and I'm battling CLM and has stunted my tree but I'm going to change that this year...I'm going to be a lot more pro-active and treat them and see if I can get my tree to a healthy state. I really want fruits next year...none SO far! Well, actually I tasted one the first year but it was sour because the tree was so immature!!

Thanks!

here in zone 9 we sometimes don't have cold or frost till january or later but the satsumas get sweet late september or october. I don't know what happened to mine this year.

papapar

Thanks papapar...does your Satsumas turn orange or do they stay green when they ripen in Sept/Oct? Its good to know they sweeten up with lack of cold weather...Hopefully, this year was just an off year for you?

they are starting to turn but still mostly green when they ripen in sept/oct, from then they will go the the orange color then the real loose peel. I sure hope this was an off year, many of the friends had a good year, ate some today, still sweet after all those freezes.

papapar

Thanks papar. Appreciate the helpful info.

Your tree is still pretty young. I'm sure it was just a fluke. If I ever get fruits I'll update.